//TIP To <b>Run</b> code, press <shortcut actionId="Run"/> or
// click the <icon src="AllIcons.Actions.Execute"/> icon in the gutter.
public class Main {
    public static void main(String[] args) {
        //TIP Press <shortcut actionId="ShowIntentionActions"/> with your caret at the highlighted text
        // to see how IntelliJ IDEA suggests fixing it.
        //System.out.printf("Hello and welcome!");
        Command command = new ConcreteCommand();
        command.setReceiver(new LowerReceiver());
        Invoker textTool = new Invoker(command);
        System.out.println("原字母为：ABANDON");
        System.out.println("字母小写后:"+textTool.call("ABANDON"));

    }
}